Work holder for lapping machine



July 15, 1958 E. CARTER ET AL WORK HOLDER FOR LAPPING MACHINE 2 Sheets-Sheet 1 Filed Oct. 26, 1955 Lyle E. Carter Robert D. Ryan INVENTORS.

BY QM July 15, 1958 L, CARTER A 2,842,906

WORK HOLDER FOR LAPPING MACHINE Filed Oct. 26, 1955 2 Sheets-Sheet 2 Lyle E. Carter Robert 0. Ryan IN V EN TORS United States Patent WORK HOLDER FOR LAPPING MACHINE Lyle E. Carter and Robert D. Ryan, Columbus, Ind.

Application ()ctober 26, 1955, Serial No. 542,888

2 Claims. (Cl. 51-216) This invention relates in general to new and useful improvements in lapping machines, and more specifically to an improved work holder for use in conjunction with lapping machines.

The average lapping machine now on the market is so manufactured whereby there can be mounted in each conditioning ring or similar component thereof only one type of article to be lapped at a time. While this arrangement may prove economically feasible in mass production work, when it is desired to lap a number of dissimilar parts with only a few of such parts being lapped, it is necessary that only like parts be placed in each conditioning ring. This results in the requiring of a relatively long period of time to lap a number of different parts.

It is therefore the primary object of this invention to provide a work holder for lapping machines which is so constructed whereby a plurality of dissimilar pieces of Work may be simultaneously mounted therein and lapped by a lapping machine.

Another object of this invention is to provide an improved work holder for lapping machines which is so constructed whereby a plurality of articles of work to be lapped may be simultaneously mounted therein and the pressure on each of the articles of work may be varied as desired.

Still another object of this invention is to provide an improved holder for lapping machines, the work holder being so constructed whereby it may be utilized in conjunction with conditioning rings of existing lapping machines without any modification whatsoever to the conditioning rings or other parts of the lapping machine.

A further object of this invention is to provide an improved work holder for lapping machines, the Work holder being provided with a plurality of work receiving recesses, each of the recesses being provided with means for applying pressure to articles of work mounted therein whereby articles of various sizes and heights may be simultaneously lapped.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure 1 is an elevational view of a conventional type of lapping machine which is now manufactured by Crane Packing Company, of Chicago, Illinois, the machine being a typical machine with which the work holder, which is the subject of this invention, may be utilized;

Figure 2 is a fragmentary horizontal sectional view taken substantially upon the plane indicated by the section line 2-2 of Figure 1 and shows the relationship of the conditioning rings of the lapping machine of Figure l with respect to the lapping plate and shows the arrangement of the work holders, which is the subject of this invention, mounted therein; 7

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Figure 3 is an enlarged top plan view of one of the' mounted within a conditioning ring and positioned relative to a lapping plate;

Figure 5 is an enlarged transverse horizontal sectional view taken through the lower part of the work holder of Figure 3 and shows the arrangement or" set screws carried by the housing of the work holder for varying the effective size of recesses formed therein;

Figure 6 is an enlarged fragmentary vertical sectional view taken through the work holder and shows the specific details of an individual spring loaded member mounted in one of the recessesthereof for applying downward pressure on work received in the recess; and

Figure 7 is an enlarged fragmentary vertical sectional view taken substantially upon the plane indicated by the section line 77 of Figure 3 and shows the manner in which the two parts of the housing of the work holder are secured together.

Referring now to the drawings in detail, it will be seen that there is illustrated in Figures 1 and 2 a conventional type of lapping machine which is referred to in general by the reference numeral 10. The lapping machine 10 includes a base 12 on which there is mounted for rotation a lapping plate 14. Also, carried by the base 12 is a suitable reservoir for a lapping fluid which is supplied to the lapping plate 12. Extending upwardly from the base 12 are suitable controls 16 for the lapping machine 10. The controls 16 include a support arm 18 having mounting heads 20 disposed in overlying relation with respect to the lapping plate 14.

Formed in the upper part of the base 12 is an opening 22 which is aligned with the lapping plate 14. Positioned within the opening 22 and supported by the heads is a plurality of conditioning rings 24. Each of the conditioning rings 24 includes an upstanding yoke 26 which has attached thereto an adjusting screw 28. The adjusting screw 28 is adjustably carried by the mounting head 26 to condition the conditioning ring 24 vertically with respect to the lapping plate 14.

Normally each of the conditioning rings 24 will carry either a plurality of small articles to be lapped, each of the articles being of the same dimension, or one large article to be lapped. However, the conditioning rings 24 are of such a nature whereby a plurality of articles of different sizes cannot be readily placed therein for simultaneous lapping. Accordingly, there have been provided the work holders which are the subject of this invention, the work holders being referred to in general by the reference numeral 34}. It is to be understood that there is one work holder St for each of the conditioning rings 24. Inasmuch as the work holders 30 are identical, only one of the work holders 30 will be described in detail hereinafter.

Referring now to Figures 3 through 7, inclusive, it will be seen that each of the work holders 30 includes a housing which is referred to in general by the reference numeral 32. The housing 32 is of a size to be snugly received in its respective conditioning ring 24. Each housing 32 is formed in two parts, the two parts including a main plate 34 and a cover plate 36. Both of the Patented July 15, 1958- plates 34 and 36 are preferably circular in outline and the cover plate 36 is secured to the main plate 34- by suitable set screws 38, as is illustrated in Figure 7. Although the housing 32 is preferably formed in two parts for ease of machining, as will be evident hereinafter, if desired, it may be formed of a single piece.

Extending vertically through the base plate 34 is a plurality of bores which form work receiving recesses 40,

42, 44, 46, 4s, s0, s2, s4, 56 and 5s. The bores whichform these various recesses open through both the upper and lower ends of the base plate 34 so that the recesses open through the underside of the housing 32. Further, the bores forming the various work receiving recesses vary in size in order that articles of work to be lapped of different cross sections or outlines may be received within the work receiving recesses in such a manner so as to prevent tipping or sliding thereof dur-' ing a lapping operation.

In order that the various work receiving recesses may. receive articles to be lapped of a size smaller than their bores and at the same time to permit the proper positioning of such articles of work therein, the article receiving recesses, with the exception of the recesses 56 and 58 are provided with adjustable screws 69. Each of these screws 60 is threadedly engaged in a threaded bore 62 which extends from its respective work receiving recess to the periphery of the main plate 34 whereby they may be adjusted externally of the housing 32; The use of the adjusting screw 60 is best illustrated witlr'respect to the work receiving recess 42 wherein an article of work 64 smaller than the recess 42 is positioned within the work receiving recess 42 by means of a pair of the set screws 60.

In order that an article of work to be lapped may be properly positioned within each of the work receiving recesses and the proper pressure applied thereto, there is mounted in each of the work receiving recesses a spring loaded member for applying downward pressure on articles received in such recesses, each of the spring loaded members being referred to in general by the reference numeral 64. Inasmuch as the spring loaded members are identical except for the sizes of certain of the components thereof, depending upon the particular work receiving recess within which they are positioned, only one of the spring loaded members 64 will be described in detail.

Referring now to Figure 6 in particular, it will be seen that there is illustrataed a portion of the work holder 30 which includes what may be considered the work receiving recess 42. Aligned with the center of the recess 42 and formed in the cover plate 36 is an internally threaded bore 66 which opens both through the upper side of the cover plate 36 and into the work receiving recess 42. Threadedly engaged in the bore 66 is an adv justing screw 68 having an enlarged upper portion 7% which is peripherally knurled to facilitate turning thereof. Further, the head of the screw 65 is provided with a screwdriver slot 72 to facilitate turning thereof.

Threadedly engaged in the lower portion of the screw 68 is a washer 74 having an internally threaded central bore 76. Secured by welding or other securing means to the underside of the washer 74 is a coil spring 78 which is partially telesco-pcd over the lower part of the screw 68. Similarly secured to the lower end of the coil spring 78 is a work engaging platae 80. The plate 80 conforms in outline to the general cross section of the work receiving recess 42.

In order that the workholder 3t) may be retained level with respect to the lapping plate 14 at all times, there is formed in the main plate 34 a plurality of small bores 82, as is best illustrated in Figure 5. Slidably mounted in the bores 82 are support pins 34 which normally project below the housing 32. The support pins 84 will rest upon the lapping plate 14 to properly sup- 5' port the housing 32, as is best illustrated in Figure 4.

In order that the support pins 34 may be utilized to level the housing 32, there is formed in the cover plate 36 an internally threaded bore 86 for each of the bores 82. Adjustably positioned in the bore 36 is an adjusting screw 88 which bears against the upper end of the associated support pin 84.

The cover plate 36 is also provided with a blind internally threaded bore 90 in the center thereof, the bore 3% opening up from the cover plate 36. Threadedly engaged in the bore 90 is the lower end of a lifting pin 92. In addition to serving for the removal of the work holder 30 from one 'of the conditioning rings 24, the lifting pin 92 may also have mounted thereon suitable weights in the event the weight of the housing 32 is not sufficient for the application of all of the combined pressure on the articles of work being lapped.

In the operation of the work holder 30, the various articles of work to be lapped are positioned in the work receiving recesses according to the size of the articles of work. The work holder 30 and the articles of work are then positioned within one of the conditioning rings 24 so that the surfaces of the article of work to be lapped are disposed in face to face engagement with the upper surface of the lapping plate 14. After the spring pressure of the work engaging plates 39 has been properly adjusted with respect to the articles of work to be lapped, the lapping machine 10 is ready to lap a plurality of articles of work which are entirely dissimilar.

Referring once again to Figure 6 in particular, it will be readily apparent that because of the adjustment of the mounting of the spring loaded members 64, the height of the articles of work to be lapped utilized in the work holder 30 may be varied within certain limits. Also, because of the use of the coil springs 78 between the washers 74 and the work engaging plate 80, it is not necessary that the upper surface of the articles of work to be lapped be parallel to the surface that is to be lapped.

From the foregoing description of the Work holder 30, it will be readily apparent that the construction thereof is extremely simple. In view of this, the manufacturing cost of the present invention is believed to be economically feasible considering the greatly increased results which may be obtained utilizing the same. It is pointed out at this time that the work holder 30 is of course not limited to the particular type of lapping. machine disclosed in this application, but may be utilized with lapping machines of all types.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A work holder for lapping machines comprising a housing having an underside and an upper side, a plurality of work receiving recesses in said housing, said recesses opening through said underside, and individual spring loaded members mounted in each of said recesses for applying downward pressure on work received in said recesses, said housing having threaded bores aligned with said recesses, said bores opening through said upper side, each of said spring loaded members including an adjusting screw threaded in one of said bores, a washer threadedly engaged on said adjusting screw, a spring element carried by said washer, and a work engaging plate carried by said spring element, whereby said work engaging plate may be selectively vertically positioned and the spring pressure thereon selectively varied.

2. A work holder for lapping machines comprising a.

5 housing having an underside and an upperside, a plurality of work receiving recesses in said housing, said recesses opening through said underside, an individual spring-loaded member mounted in each of said recesses for applying downward pressure on work received in said recesses, said housing having threaded bores aligned with said recesses, said bores opening through said upper side, each of spring-loaded member including an adjusting screw threaded in one of said bores, a washer threadedly engaged on said adjusting screw, :1 spring element carried by said washer, and a work-engaging plate carried by said spring element, said work-engaging plate corresponding in shape and size to its respective recess, whereby said work-engaging plate may be selectively vertically positioned and the spring pressure thereon selectively varied.

References Cited in the file of this patent UNITED STATES PATENTS Great Britain Nov. 21, 1951 

